Probably the oil in the mayo. I read up on this somewhere
authoratative, can't recall the source, but it was evap or replace ie
alcohol or oil. Goes to the peanut butter concept too.

On Apr 6, 12:45*pm, wrote:
I know this sounds like an old wives tale but try mayonnaise. *I
picked this up from somewhere (probably the internet) several years
ago but it worked to remove a white cup stain from a piece of
production-built office furniture (suspect the finish is lacquer).
Apply the mayo to the spot using your fingertips and continue to rub
in circles, keeping the stain wet. *It took two attempts to get the
stain to pretty much disappear.

On the other hand, the effect was less favorable on a piece that I am
certain was finished with poly. *Helped but didn't fix. *The Mayo oil
probably had more of a problem penetrating.

RonB